The present invention relates to a hollow plastic bottle with an improved base.
Hollow plastic bottles generally include a recessed or inwardly extending or reentrant base structure. This type of base has been found to have good resistance to deformation, especially deformation caused by the effects of internal pressure.
However, it is desirable to provide a recessed base structure for hollow plastic bottles with improved strength properties. For example, increased strength properties in the recessed base will facilitate use of the container for increased heat applications, as pasteurization. Also, increased strength properties will improve impact strength, minimizing damage when the bottles are accidentally dropped. Further, improved strength properties in the base will help prevent roll-out, i.e., under pressure or heat the plastic bottles tend to roll-out or bulge at the base.
It is, therefore, a principal object of the present invention to provide a hollow plastic bottle with an improved base.
It is a further object of the present invention to provide an improved plastic bottle as aforesaid with improved strength properties in the base.
It is a still further object of the present invention to provide an improved plastic bottle as aforesaid which is easy to prepare and which is aesthetically pleasing.
Further objects and advantages of the present invention will appear hereinbelow.
It has now been found that the foregoing objects and advantages are readily obtained in accordance with the present invention.
The hollow plastic bottle of the present invention comprises: a hollow body of thermoplastic material having a generally cylindrical side wall, an upper end with a dispensing opening therein, and a lower supporting base with an inwardly extending portion thereof, wherein said base includes a continuous outer supporting annular rim for supporting the bottle on a surface and a central portion of the base. In addition, the space between the central portion of the base and the outer supporting rim includes a plurality of struts extending radially from the central portion of the base towards said annular rim.
The plastic bottle is desirably blow molded, desirably biaxially oriented, and polyethylene terephthalate is a preferred material.
Preferably, from 6-10 of the struts are provided, the struts extend over a substantial portion of the base and may extend substantially to the annular rim, and desirably the struts extend outwardly from the plane of the base.
The plastic bottle of the present invention has improved strength properties so that the container may be effectively utilized for increased heat applications, as for example, pasteurization, without adverse effects. In addition, the container of the present invention is less susceptible to roll-out or bulging at the base, and has improved impact properties.
Further features and advantages of the present invention will appear hereinbelow.